a-a a-b aaa aab aam aao aar aas aax ab- aba abb abm abo abr abs abx ama amb amm amo amr ams amx aoa aob aom aoo aor aos aox ar- ara arb arm aro arr ars arx as- asa asb asm aso asr ass asx ax- axa axm axo axr axs axx baa bab bam bao bar bas bax bba bbb bbm bbo bbr bbs bbx bma bmb bmm bmo bmr bms bmx boa bob bom boo bor bos box bra brb brm bro brr brs brx bsa bsb bsm bso bsr bss bsx bxb bxm bxo bxx m-o m-r maa mab mam mao mar mas max mba mbb mbm mbo mbr mbs mbx mma mmb mmm mmo mmr mms mmx moa mob mom moo mor mos mox mra mrb mrm mro mrr mrs mrx msa msb msm mso msr mss msx mxa mxr mxs oaa oab oam oao oar oas oax ob- oba obb obm obo obr obs obx om- oma omb omm omo omr oms omx oo- ooa oob oom ooo oor oos oox or- ora orb orm oro orr ors orx os- osa osb osm oso osr oss osx ox- oxa oxb oxo oxx ra- raa rab ram rao rar ras rax rba rbb rbm rbo rbr rbs rbx rma rmb rmm rmo rmr rms rmx roa rob rom roo ror ros rox rra rrb rrm rrr rrs rsa rsb rsm rso rsr rss rsx rxr rxs saa sab sam sao sar sas sax sba sbb sbm sbo sbr sbs sbx sma smb smm smo smr sms smx soa sob som soo sor sos sox sr- sra srb srm sro srr srs srx ss- ssa ssb ssm sso ssr sss ssx sxm sxs xaa xam xar xas xbr xbx xma xmm xmo xmr xms xmx xoa xom xoo xor xos xox xrx xsa xsb xsm xss xxo xxx